FIG. 1 is a high-level diagram used to illustrate a conventional IEEE 802.11 compliant wireless network 100 (also known as Wireless Fidelity (WiFi)). The 802.11 architecture includes several main components: one or more stations (STA) 102, one or more wireless access points (AP) 104, one or more basic service sets (BSS) 106 (sometimes referred to as just service sets (SS)), and a distribution system (DS) 108. As will be appreciated, the STAs and wireless APs are physical hardware devices. The BSS 106a is a wireless network having a single wireless AP 104a supporting one or multiple wireless STAs or clients 102a. Each BSS 106 itself can be referred to as a wireless network. The STAs in a particular BSS communicate through that BSS' AP which provides connectivity to a backbone network. In the embodiment shown, the APs 104 of multiple BSSs 106 are interconnected by the DS 108, but may necessarily communicate with each other, and may interface with system controller (not shown).
The current scanning scheme (scanning for access points) is specified in the 802.11 standard, which standards (including all versions) are hereby incorporated by reference. Currently, each AP is capable of employing up to fourteen (14) channels (the actual number depends on the location of implementation) and in the United States there are eleven (11) channels. The conventional scanning scheme typically proceeds with the STA scanning all channels and staying at each channel for a specified maximum time. For this, there are two types of scanning: active scanning (probe request/response) and passive scanning (beacon). In active scanning, the STA broadcasts a probe request (802.11) on each of the channels. This probe request utilizes a zero-length broadcast service set identifier (SSID). Upon receipt of the probe responses, the STA adds the BSSIDs included in those responses to the BSSID scan list stored in its memory. In passive scanning, the STA does not transmit a probe request, but instead dwells on each channel for a predetermined time period and adds BSSIDs included in any received beacons to the BSSID scan list stored in its memory.
The main problem with the conventional scanning techniques is the amount of time consumed (or delay) in order to complete a scan—the processing is performed at the media access control (MAC) layer. In the 2.4 GHz band, scanning through all supported channels can take upwards of 2 seconds, and in the 5 GHZ band can take upwards of 3 seconds. Further, the time waiting to receive the beacons in each channel in passive scanning in order to match the STA's desired BSSID information may be significant. Additionally, active scanning requires scans in each channel until the probe timer reaches a maximum channel time.
Accordingly, there are needed methods, devices and systems that allow or enable the STA to listen/scan the channels and check at the same time for the received SSID/BSSID (of a particular channel). This may be accomplished by processing at PHY layer rather than the MAC layer.